We are currently doing 2 baths and a kitchen. We have been to several stores to look at quartz and will end up with countertops from two different companies. The Ikea at our location said their quartz is by Silestone so I wonder if brand varies by location.
My advice is to locate actual Ceaserstone/Silestone/Cambria etc. showrooms and view the slabs you are interested. These showrooms were about an hour away from us but clustered within 10 miles of each other. Take a day off, visit 2 or 3 showrooms and bring home samples (larger samples will have to be ordered). It makes a huge difference when you see the whole slab (if you have them available, take samples of your floor, paint and cabinet color).After you narrow it down, order as large a sample as you can get and set it in your kitchen and see how it wears. We loved the way some of the Matte/Suede/Honed finishes looked but could already tell they would be more maintenance than the polished quartz after having the samples sit by the sink for a week. Also shop around. We discovered some stores told us one of our countertops was only available by the slab while another store said we could just buy what we needed.
Best of luck!

My quartz from IKEA is Caesarstone. We've had them about two years, and absolutely no issues, but they are the traditional glossy finish. Ours are Organic White (perimeter) and Piatra Grey (island.)

I just had grey silestone counters installed in 2 baths in a new build. They look gorgeous. I am very happy with the light grey color.

I like lighter counters, black ones suck up the light in a space. To see if you would like black counters take black trash bags and cover all your counters, do you like that big plane of black?

Another reason I like lighter counters, is to see stuff on the counter. Refilling the pepper grinder I always spill some peppercorns, black counter I would never see them.

Go to a solid surface shop and get a fabricator who will template on site. There must be a million possibilities, and beware any matte quartz is more maintenance than a gloss.

In fact, if you want black and matte, do a honed absolute black granite, or the same in leathered finish. No reason you must have quartz for that look.

Research matte quartz before proceeding. I have read many threads with complaints about them here.